Miguel Nicolelis, Duke University"We are trying to investigate how could we tap into brain signals" real 28k

Wednesday, 15 November, 2000, 19:37 GMT

Monkey brain operates machine

Scientists have used the brain signals from a monkey to drive a robotic arm.

As the animal stuck out its hand to pick up some food off a tray, an artificial neural system linked into the animal's head mimicked the activity in the mechanical limb.

It was an amazing sight to see the robot in my lab move, knowing that it was being driven by signals from a monkey brain

Mandayam Srinivasan, MIT

The system was even used to remotely control another robot arm 950 kilometres (600 miles) away in a different lab.

This is not the first time that a device has been operated by "brain power" alone, but the experiment marks a significant step forward in sophistication.

It holds out the prospect that, one day, paralysed patients might be able to command the movement of prosthetic limbs that have been "wired" into their brains.

Commenting on the research, Sandro Mussa-Ivaldi, of the Northwestern University Medical School, and the Rehabilitation Institute of Chicago, Illinois, US, said: "The idea of driving robotic limbs with what effectively amounts to the mere power of thought was once in the realm of science fiction. But this goal is edging closer to reality."

Net connection

Miguel Nicolelis, of Duke University, Durham, North Carolina, US, and colleagues, implanted an array of electrodes in several areas of a monkey's brain known to be involved in motor function.

Miguel Nicolelis, his monkey and the robotic arm

The electrodes were used to record brain activity as the animal learned reaching tasks, including reaching for small pieces of food placed randomly at four locations on a tray.

The mass of neural signal data generated during many repetitions of these tasks was fed into a computer, which analysed the information and matched it to the trajectory of the monkey's hand.

Every time the monkey then moved its hand to grab the food, the computer was able to process the brain signals to make similar, real-time, three-dimensional movements in a robotic arm. The signals were even sent over a standard internet connection to control another arm in the Massachusetts Institute of Technology's "Touch Lab".

"It was an amazing sight to see the robot in my lab move, knowing that it was being driven by signals from a monkey brain at Duke," said Touch Lab director and co-researcher Mandayam Srinivasan. "It was as if the monkey had a 600-mile- (950-km-) long virtual arm."

Brain study

In previous research, it has been shown that a rat wired into an artificial neural system can make a robotic water feeder move just by willing it.

The idea of driving robotic limbs with what effectively amounts to the mere power of thought was once in the realm of science fiction

Sandro Mussa-Ivaldi, Rehabilitation Institute of Chicago

But the latest work sets new benchmarks because it shows how to process more neural information at a faster speed to produce more sophisticated robotic movements. That the system can be made to work using a primate is also an important proof of principle.

Miguel Nicolelis told BBC News Online that people would obviously focus on possible future applications for quadriplegics but he said the system also offered a new way to probe the workings of the brain.

"We have designed a new paradigm to study how the brain processes information," he said.

"Until fairly recently, we tried to understand the brain by looking at one neuron at a time, but we all know the brain works in a parallel mode requiring the activation of huge numbers of cells to produce any behaviour.

"So the implementation of this technique for recording up to a 100 neurons in primates is a big deal for science."